Safety cover plate for electrical outlets



Jan. 7, 1958 A. ca. HESS 2,313,991

SAFETY COVER PLATE FOR ELECTRICAL OUTLETS Filed Aug. 24, 1956 4 INVENTOR. v 44 WW 6. HESS,

United States Patent SAFETY COVER PLATE FOR ELECTRICAL OUTLETS Alvin G. Hess, St. Petersburg, Fla.

Application August 24, 1956, Serial No. 606,063

3 Ciaims. (Cl. 220--24.3)

This invention relates to electrical receptacles or outlets, and more particularly, has reference to a cover or face plate for a receptacle of this type, so designed as to normally cover the prong-receiving slots of the receptacle.

It is well known that electric shocks are often suffered by small children, by reason of the fact that the child may insert a hairpin or the like into the prong-receiving slotof an exposed receptacle. Alternatively, the child may pull the plug of an appliance cord out of the receptacle, and may incur an electric shock in doing so by inserting his finger between the plug and receptacle after partially extracting the plug.

In view of the above, the main object of the present invention is to provide a safety cover plate for a conventional electrical receptacle, so designed as to completely cover the prong-receiving slots of the receptacle when the receptacle is not in use, to deny access to the receptacle so far as infants or small children are coni cerned. I

Another object of the invention is to so design the cover means for the receptacle as to permit the same to be opened only responsive to the exertion of a pressure of a value such as to prevent the child from opening the cover means, while still permitting the cover means to be readily opened by an adult, e

A further object is to provide a safety cover plate for electrical receptacles of the character described which is operatively associated with a wholly conventional receptacle responsive to no more than removal of the conventional face plate ordinarily associated with the receptacle, and substitution of the safety plate constituting the present invention, the same attaching screw previously used for connecting the conventional cover plate to the receptacle being employed for the purpose of connecting thereto the safety cover plate. 7

Another object is to provide a cover plate of the character described that will be adapted for manufacture at a relatively low cost, considering the benefits to be obtained from the use thereof, the cover plate, in this regard, including a plate member Which can be stamped in a single piece of material and, when so stamped, provides hinges, support means, etc. for the various rnovable components of the device.

Still another object is to so form the device as to incorporate therein pivoted cover flaps, arranged in pairs, the flaps of each pair coverin one of the units of an ordinary duplex receptacle, to permit exposure of either unit Without requiring accompanying exposure of the unit not in use.

Still another object is to so form the flaps that when opened to permit insertion of an electric plug in the unit, they will grip the plug in manner such as to prevent removal of the plug by a small child, said removal of the plug being effected only responsive to depression of the button used for initially opening the flaps, which button is not capable of being depressed except when the pressure exceeds in value that which an infant would be able to apply to the button.

Other objects will appear from the following description, the claims appended thereto, and from the annexed drawings in which like reference characters designate like parts throughout the several views, and wherein:

Figure 1 is a front elevational view of a safety cover plate for electrical receptacles according to the present invention;

Figure 2 is a longitudinal sectional view therethrough substantially on line 22 of Figure 1, the dotted lines indicating an outlet box and a conventional receptacle;

Figure 3 is a longitudinal sectional view through the flap-operating mechanism substantially on line 3-3 of Figure l, the fiaps being shown in their raised position in dotted lines;

I Figure 4 is a rear elevational view of the safety cover plate; and

V Figure 5 is an enlarged detail sectional view on line 55 of Figure 1. v

. Referring to the drawings in detail, designated at 10 is an outlet box, adapted to be mounted in a wall W, and at 12 there has been generally designated a conventional duplex receptacle. This includes the usual spaced, identically formed outlets 14 each of which would have a pair of prong-receiving slots to receive an electric plug, not shown.

This is conventional construction, and ordinarily a face plate is secured in position to the wall W, said face plate having openings snugly receiving the electrical outlets, so that the prongs are exposed for insertion of plugs into the slots.

in accordance with the present invention, the ordinary face or cover plate is removed, and there is applied in place thereof the safety cover plate 16 constituting the presentinvention. This includes a planiform plate element 18 integrally formed at its periphery with a rearwardly projecting flange 20 adapted to engage against the Wall surface W, to space the plate element 18 outwardly therefrom.

Centrally formed in the plate element is an opening adapted to receive the connecting screw 22, which is threadable into the body of the duplex receptacle, so as to secure the face plate to the receptacle. Screw 22 is the same as is ordinarily used to hold conventional face plate in position.

Formed in the plate element are longitudinally spaced openings 24 adapted to receive the projecting portions of the outlets 14, in the same manner as the conventional face plate. However, there is a difference between the arrangement of the projecting portions of the outlets and the face plate of the invention, as compared to that conventionally found. This difference resides in the fact that the plate element 18 is spaced outwardly from the Wall W a distance which may be slightly greater than the distance that an ordinary face plate is spaced from the Wall. The plug-receiving portions lid of a conventional duplex receptacle ordinarily project slightly beyond the plane of an ordinary face plate. However, in the present invention said plug-receiving portions, while they may project as far as the plane of the plate element, would not ordinarily project therebeyond. This is due to the fact that cover flaps are mounted upon the plate ele ment of the present invention, and in their closed position, have flanged edges which are disposed substantially in the plane of the plate element.

in any event, mounted upon the plate element 18 are spaced pairs of cover flaps, the flaps of each pair being designated 26, The cover flaps are of rectangular formation, and are adapted to completely cover the openings 24 when in closed position, as shown in Figure l.

,The cover flaps 26, 28 of each pair are formed with flanges extending peripherally thereof and facing toward the plane of the plate element 18.. The flaps are hinged along their outer or back edges, and the flanges of the inner or front edges of the flaps are formed at uniformly spaced intervals with triangularly shaped or pointed teeth 2! which are struck inwardly from the material of the flanges of the inner edges, the teeth of the flaps 26, 28 being designated at 27, 29 respectively and being shown to particular advantage in Figure 5.

The outer flaps 26 of the respective pairs have at their opposite sides hinge sleeves integrally formed from the material of the flanges of the back or outer edges thereof. The hinge sleeves of the outer flaps embrace elongated hinge sleeves 30 formed of the material of the plate element 18, and hinge pins 32 are extended through the registering hinge sleeves of the plate element and outer flaps 27.

The inner flaps 28 are similarly formed, and are connected to hinge sleeves 34 struck or formed out of the material of the plate element, by means of hinge pins 36.

It will be seen that the flaps of the respective pairs are thus pivoted to swing between the full and dotted line positions of Figure 3, about axes extending transversely of the plate elements at opposite sides of the re spective openings 24.

Means are associated with the several flaps normally holding the same in tightly closed position. Said means comprises, for the outer flaps 26, leaf springs 38 extend ing longitudinally of the plate element T8 in contact with the underside of the plate element, adjacent one side of the flaps 2s. The leaf springs 38 have outer ends tightly engaged in slotted lugs 39 fixedly secured to the underside of the plate element 13. It will be understood that the slotted lugs can be defined by striking the material of the plate element 13 inwardly, or alternatively, the plate element 18, if formed of a moldable material, could be molded internally with the slotted lugs.

in any event, the springs 38 are secured fixedly in any suitable manner to the plate element 18, and have free ends oltset outwardly of the plate element as shown in Figure 2, said free ends being extended through slots 4t) formed in the plate element 16 and being extended through guides 41 secured to the undersides of flaps 26. The free ends of the leaf springs are slidable on the guides 41. The leaf springs are so tensioned as to normally bias the flaps 26 to the closed position thereof.

For maintaining the flaps 28 in a normally closed position, a single leaf spring 42 is provided, the intermediate portion of which is engaged in a slotted lug 43 secured to the underside of plate element 18 (see Figure 2). The ends of the spring 4-2 are both offset outwardly of the plane of plate element 18, extending through slots 44 formed in the plate elements. The ends of leaf spring 42 are slidably engaged in guides 45 secured to the undersides of the flaps 28.

By reason of this arrangement, the flaps are resiliently, yieldably biased to closed position, but are capable of being swung to open positions to permit the insertion of an electric plug or the removal of said plug, against the restraint of the leaf springs 38, 42.

At one side of the respective pairs of flaps there are provided buttons 46, depressible in a path perpendicular to the plane of the plate element 18. The buttons 46 are slidably engaged in openings 47 of the plate element, and have circumferential lips on their inner ends limiting movement of the buttons in a direction outwardly of the plate clement.

Formed on the inner ends of the buttons 26' are axially extending tugs d8, engaged in registering openings formed on the inner ends of levers or lifting arms 50, that are rockably mounted on the plate element through the medium of apertured lugs 52 formed on the underside of the plate element.

The levers 50, as shown in Figure 4, extend in opposite directions from each button, and are fulcrumed on the plate element intermediate the ends of the levers.

At the ends of the levers remote from the buttons 46,

the levers are formed with fingers 5 5 projecting through openings formed in the plate element lb into engagement with the respective flaps 26, 23. The fingers bear against the flaps adjacent the hinge axes of the flaps, and thus it will be seen that on depression of a button 46, the levers will be rocked about their fulcrums, to shift the fingers 54 to the right in the Figure 3, whereby to bias the flaps 26, 2d simultaneously about their hinge axes to open positions shown in doted lines in Figure 3.

The construction is such as to require the exertion of a predetermined amount of pressure against the buttons 45, before they can be depressed sutliciently to swing the flaps to open positions. This pressure is determined by the strength of the springs 38. The amount of pressure required would be established at a value such that the buttons could not be depressed by a small child, being depressible only by a person having an adults strength.

In use of the device, if it is desired to insert an electric plug in a selected plug-receiving portion 14 of the receptacle, one depresses the selected button 46, to swing the flaps 26, 28 associated with said portion to open position. The plug is now inserted, with the button held depressed to an extent sufficient to hold the flaps completely out of engagement with the plug. When the plug has been fully inserted, the button 46 is released and the springs 38, d2, tending to return to their normal position, bias the flaps 26, 223 into engagement with opposite sides of the inserted plug, to firmly grip the plug and hold the same against removal from the receptacle. in this connection, the teeth 27, 29 will now be disposed in positions in which they converge in the direction of the plate element 18, and this will of course cause said teeth to bite alt) into the opposite sides of the plug to hold the same against removal by a child. Whenever the plug is to be removed, however, one may press the button 46 sufliciently to swing the flaps away from the plug, after which the plug is removed and the button released, with the flaps now returning to their fully closed positions.

It is believed apparent that the invention is not necessarily confined to the specific use or uses thereof described above, since it may be utilized for any purpose to which it may be suited. Nor is the invention to be necessarily limited to the specific construction illustrated and described, since such construction is only intended to be illustrative of the principles, it being considered that the invention comprehends any minor change in construction that may be permitted within the scope of the appended claims.

What is claimed is:

l. A safety cover plate for a duplex electrical receptacle comprising: a plate element having a pair of like plug-receiving openings; a pair of cover flaps overlying each opening, the flaps of each pair being hinged to the plate element at opposite sides of the associated opening for swinging movement outwardly of the plate element from a normal position closing the opening, the flaps of each pair having side portions projecting laterally substantial distances beyond the respective sides of the associated opening to overlie the plate element along opposite sides of the opening, the plate element having a plurality of apertures at one side of each opening; a button mounted adjacent each opening in one of the apertures for depression therein by a user; a pair of levers extending from each button, said levers being fulcrumed intermediate their ends on the underside of the plate element wholly outside the area of the adjacent opening, and being engaged at one end by the associated button so as to be rocked responsive to depression of the button, said levers including fingers at their other ends projecting through others of said apertures into engagement with one of the side portions of the respective flaps; and resilient, yielding means carried by the plate element in engagement with the respective flaps and tensioned to bias the flaps to said normal position thereof.

2. A safety cover plate for a duplex electrical receptacle comprising: a plate element having a pair of like plug-receiving openings; a pair of cover flaps overlying each opening, the flaps of each pair being hinged to the plate element at opposite sides of the associated opening for swinging movement outwardly of the plate element from a normal position closing the opening, the flaps of each pair having side portions projecting laterally substantial distances beyond the respective sides of the associated opening to overlie the plate element along 0pposite sides of the opening, the plate element having a plurality of apertures at one side of each opening; a button mounted adjacent each opening in one of the apertures for depression therein by a user; a pair of levers extending from each button, said levers being fulcrumed intermediate their ends on the underside of the plate element wholly outside the area of the adjacent opening, and being engaged at one end by the associated button so as to be rocked responsive to depression of the button, said levers including fingers at their other ends projecting through others of said apertures into engagement with one of the side portions of the respective flaps; and resilient, yielding means carried by the plate element in engagement with the respective flaps and tensioned to bias the flaps to said normal position thereof, comprising leaf springs on the plate element slidably connected to the respective flaps, said leaf springs lying substantially Wholly outside the area of the opening in contact with the other side portions of the flaps.

3. A safety cover plate for a duplex electrical receptacle comprising: a plate element having a pair of like plug-receiving openings; a pair of cover flaps overlying each opening, the flaps of each pair being hinged to the plate element at opposite sides of the associated opening for swinging movement outwardly of the plate element from a normal position closing the opening, the flaps of each pair having side portions projecting laterally substantial distances beyond the respective sides of the associated opening to overlie the plate element along opposite sides of the opening, the plate element having a plurality of apertures at one side of each opening; a button mounted adjacent each opening in one of the apertures for depression therein by a user; a pair of levers extending from each button, said levers being fulcrumed intermediate their ends on the underside of the plate element wholly outside the area of the adjacent opening, and being engaged at one end by the associated button so as to be rocked responsive to depression of the button, said levers including fingers at their other ends projecting through others of said apertures into engagement with one of the side portions of the respective flaps; and resilient, yielding means carried by the plate element in engagement with the respective flaps and tensioned to bias the flaps to said normal position thereof, comprising leaf springs on the plate element slidably connected to the respective flaps, said leaf springs lying substantially wholly outside the area of the opening in contact with the other side portions of the flaps, one of the leaf springs extending at its ends under adjacent flaps of the respective pairs, so as to be common to said adjacent flaps.

References Cited in the file of this patent UNITED STATES PATENTS 900,773 Patterson Oct. 13, 1908 961,720 Hubbell June 14, 1910 1,083,716 Weber Jan. 6, 1914 1,212,792 Mantel Jan. 16, 1917 1,263,604 Royster Apr. 23, 1918 1,579,865 Hubbell Apr. 6, 1926 2,092,904 Brugger Sept. 14, 1937 

